// The incident queue: filter chips and a list of incident rows.

import * as api from './api.js';
import { h, clear, badge, emptyState, spinner } from './ui.js';
import { age, until, isFuture, severityClass, labelSummary } from './format.js';
import { state, myID } from './state.js';
import { navigate } from './app.js';

// The same filters as the TUI's `f` cycle, plus archived ones to get back to.
const FILTERS = [
  { id: 'open', label: 'Open', query: { sort: 'severity' } },
  { id: 'triggered', label: 'Triggered', query: { status: 'triggered', sort: 'severity' } },
  { id: 'acknowledged', label: 'Acked', query: { status: 'acknowledged', sort: 'severity' } },
  { id: 'snoozed', label: 'Snoozed', query: { snoozed: 'true' } },
  { id: 'resolved', label: 'Resolved', query: { status: 'resolved' } },
  { id: 'archived', label: 'Archived', query: { status: 'resolved', archived: 'true' } },
];

const EMPTY = {
  open: ['All clear', 'Nothing open right now.'],
  triggered: ['Nothing triggered', 'Every open incident has been acknowledged.'],
  acknowledged: ['Nothing acknowledged', 'No one is working an incident right now.'],
  snoozed: ['Nothing snoozed', 'Snoozed incidents show up here until the snooze runs out.'],
  resolved: ['Nothing resolved', 'Resolved incidents are archived after a while.'],
  archived: ['Nothing archived', ''],
};

let filter = loadFilter();
let items = null; // null while loading
let error = null;
let selected = null;
let cursor = -1; // keyboard position in the list
let built = false;

function loadFilter() {
  try {
    const f = sessionStorage.getItem('terdut.queue.filter');
    if (FILTERS.some((x) => x.id === f)) return f;
  } catch {
    /* storage unavailable */
  }
  return 'open';
}

function saveFilter() {
  try {
    sessionStorage.setItem('terdut.queue.filter', filter);
  } catch {
    /* storage unavailable */
  }
}

export function show(incidentID) {
  selected = incidentID;
  if (!built) {
    renderChips();
    built = true;
  }
  renderList();
}

export async function refresh({ fresh = false } = {}) {
  const f = FILTERS.find((x) => x.id === filter);
  const requested = filter;
  try {
    // The open list is already fetched for the badges; no need to ask twice.
    const result = filter === 'open' && !fresh ? state.open : await api.incidents(f.query);
    if (requested !== filter) return;
    items = result;
    error = null;
  } catch (err) {
    if (requested !== filter) return;
    error = err.message;
  }
  renderList();
}

function setFilter(id) {
  if (id === filter) return;
  filter = id;
  saveFilter();
  items = null;
  cursor = -1;
  renderChips();
  renderList();
  refresh({ fresh: true });
}

function renderChips() {
  const el = document.getElementById('queue-filters');
  clear(el, FILTERS.map((f) =>
    h('button', {
      class: 'chip',
      type: 'button',
      role: 'tab',
      'aria-selected': String(f.id === filter),
      onclick: () => setFilter(f.id),
      text: f.label,
    }),
  ));
}

function renderList() {
  const el = document.getElementById('queue-list');
  if (error && !items) {
    clear(el, h('div', { class: 'load-error', text: error }));
    return;
  }
  if (!items) {
    clear(el, spinner());
    return;
  }
  if (!items.length) {
    const [title, text] = EMPTY[filter];
    clear(el, emptyState(title, text, filter === 'open' ? 'checkCircle' : null));
    return;
  }
  clear(el,
    error && h('div', { class: 'load-error', text: `Showing older data: ${error}` }),
    items.map((inc, i) => row(inc, i)),
  );
}

function row(inc, index) {
  const snoozed = isFuture(inc.snoozed_until);
  const resolved = inc.status === 'resolved';

  let status;
  if (resolved) status = badge('Resolved', 'st-resolved');
  else if (snoozed) status = badge(`Snoozed · ${until(inc.snoozed_until)}`, 'st-snoozed');
  else if (inc.status === 'acknowledged') {
    const by = inc.acknowledged_by_id === myID() ? 'you' : inc.acknowledged_by;
    status = badge(`Acked${by ? ' · ' + by : ''}`, 'st-acknowledged');
  }
  else status = badge('Triggered', 'st-triggered');

  let assignee = null;
  if (inc.assigned_to_id != null) {
    assignee = h('span', { text: inc.assigned_to_id === myID() ? '→ you' : `→ ${inc.assigned_to}` });
  }

  // The server already puts the group labels in the title; show only the rest.
  const labels = labelSummary(Object.fromEntries(
    Object.entries(inc.group_labels || {}).filter(([k, v]) => !inc.title.includes(`${k}=${v}`))));
  return h('a', {
    class: `row ${severityClass(inc.severity)} ${resolved ? 'resolved' : ''} ${index === cursor ? 'kbd-focus' : ''}`,
    href: `/incidents/${inc.id}`,
    'aria-current': inc.id === selected ? 'true' : null,
    dataset: { index: String(index) },
  },
    h('div', { class: 'row-title', text: inc.title }),
    h('div', { class: 'row-age', title: inc.triggered_at, text: age(inc.triggered_at) }),
    h('div', { class: 'row-meta' },
      status,
      assignee,
      labels && h('span', { class: 'labels', text: labels }),
    ),
  );
}

// key handles j/k/enter on the list. Returns true when it used the key.
export function key(e) {
  if (!items || !items.length) return false;
  if (e.key === 'j' || e.key === 'ArrowDown') {
    cursor = Math.min(items.length - 1, cursor + 1);
  } else if (e.key === 'k' || e.key === 'ArrowUp') {
    cursor = Math.max(0, cursor - 1);
  } else if (e.key === 'Enter' && cursor >= 0) {
    navigate(`/incidents/${items[cursor].id}`);
    return true;
  } else if (e.key === 'f') {
    const i = FILTERS.findIndex((x) => x.id === filter);
    setFilter(FILTERS[(i + 1) % FILTERS.length].id);
    return true;
  } else {
    return false;
  }
  renderList();
  const el = document.querySelector(`#queue-list [data-index="${cursor}"]`);
  if (el) el.scrollIntoView({ block: 'nearest' });
  return true;
}